The three-dimensional Graphical Kernel System is designed to provide a basic set of 3D function with hooks for incorporating hidden-line/hidden-surface removal. Every attempt has been made to ensure full compatibility with GKS so that programs can run unmodified in the GKS-3D environment. For effective operation in a 3D environment, GKS-3D provides a full set of viewing operations that can support not only the widely known synthetic camera model but also special viewing models tailored to the application.